1. Field of the Invention
The present invention relates to a sheet feeding apparatus for feeding a sheet and an image forming apparatus provided with the sheet feeding apparatus.
2. Description of the Related Art
Generally, an image forming apparatus such as a copying machine, a laser beam printer, or a facsimile is provided with a sheet feeding apparatus which automatically feeds a sheet into an image forming portion one by one. The sheet feeding apparatus is provided with a sheet storage case which stores a feeding sheet and the sheet storage case is movable onto a rail installed on a feeding apparatus body so as to pull out it when a user replenishes the sheet. Further, a pull-out stopper is provided on the rail to regulate a pull-out degree of the sheet storage case, and thus it can prevent the sheet storage case from being easily fallen off at the time of being pulled out by the user.
In the image forming apparatus, recently, there is a growing need for the sheet feeding apparatus having the sheet storage case capable of storing the sheets in large numbers so as to reduce a user's burden of loading the sheets. In a case of providing the high-capacity sheet storage case, since the weight of sheets increases, the strength of the sheet storage case itself is required. Therefore, the weight of the sheet storage case itself also tends to increase. For this reason, when the sheet storage case is pulled out and the weight of the sheet storage case is supported by the rail, an excessive force (moment) is applied to the rail, and thus deformation or breakage of the rail may be generated.
With respect to this, the sheet feeding apparatus has been proposed that supports the weight of the sheet storage case by allowing a storage case caster provided on a bottom of the sheet storage case to come in contact with a floor when the sheet storage case is pulled out (see Japanese Patent Laid-Open Nos. 2007-161448 and 2006-346156).
However, existing sheet feeding apparatuses may not support the sheet storage case when the image forming apparatus is installed on a place, for example, a stepped place or a desk where the storage case caster comes in not contact with the floor at the time of pulling out the sheet storage case. Here, the weight of the sheet storage case when the sheet storage case is pulled out is generally supported by an interlocked portion of the rail and the sheet storage case in the feeding apparatus body. Accordingly, in order to support the high-capacity sheet storage case, the sheet feeding apparatus capable of increasing the strength by a multistage rail is disclosed in Japanese Patent Laid-Open No. 2006-346156, but there have been problems that the configuration of the rail becomes complicated and the cost also becomes high.
Accordingly, the present invention provides the sheet feeding apparatus capable of supporting the sheet storage case with a simple configuration and the image forming apparatus provided with the sheet feeding apparatus.